The role of electroneuromyography evaluation of the bulbocavernosal reflex in the diagnosis of pelvic nerve damage in patients with chronic pelvic pain syndrome

Abstract

Introduction. One of the additional instrumental methods for diagnosing pudendal neuropathy is needle electroneuromyography (ENMG) of the bulbocavernosus reflex (BCR). The accumulated data on ENMG BCR in patients with primary chronic pelvic pain syndrome (CPPS) are insufficient due to the specificity of the procedure and its performance only in expert centres that specialise in the treatment of pelvic pain. Therefore, a study to investigate the features of ENMG BCR in patients with CPPS is of increased interest.Objective. To assess the representativeness and informativeness of the ENMG BCR technique in patients with CPPS and to identify factors influencing changes in the main parameters of the BCR M-response such as latency, amplitude, and duration.Materials & methods. Retrospective cohort study, which included 75 data from patients with (CPPS) who underwent needle-guided ENMG recording of BCR. Subjective complaints of patients were recorded using validated questionnaires: visual analogue scale (VAS) and chronic prostatitis and male pelvic pain syndrome symptom scale index (NIH-CPSI). Basic ENMG parameters such as the amplitude, latency, and duration of the M-responses were recorded.Results. We found statistically significant correlations between the duration and height of the M response of the patients (r = 0.31, p = 0.03) and their body weight (r = 0.34, p = 0.02). Anthropometric data did not correlate with amplitude and latency. Significant excess latency above 45 ms was observed, confirming nerve tissue destruction, in 11 (55%) women and 24 (44%) men. Although there were no statistically significant differences in any of the M-response parameters between men and women, there was a tendency for an increase in response amplitude in men and an increase in BCR latency time in women.Conclusion. The results of our study show that the duration of the M-response of BCR can correlate positively with the anthropometric data of the patient. At the same time, the mean latency and amplitude of the response are independent of anthropometric data, and the difference between them may be more determined by sex differences.